From 3d2e3beafefa58da4d6cf2f68fe06319dad08626 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Thu, 9 Jun 2016 00:54:32 -0700
Subject: [PATCH] Add serde_codegen::expand to avoid public Syntex dependency

---
 README.md                              | 10 ++--------
 examples/serde-syntex-example/build.rs |  5 +----
 serde_codegen/src/lib.rs               | 12 ++++++++++++
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 03093081..ec8564c9 100644
--- a/README.md
+++ b/README.md
@@ -142,10 +142,7 @@ pub fn main() {
     let src = Path::new("src/main.rs.in");
     let dst = Path::new(&out_dir).join("main.rs");
 
-    let mut registry = syntex::Registry::new();
-
-    serde_codegen::register(&mut registry);
-    registry.expand("", &src, &dst).unwrap();
+    serde_codegen::expand(&src, &dst).unwrap();
 }
 ```
 
@@ -203,10 +200,7 @@ mod inner {
         let src = Path::new("src/main.rs.in");
         let dst = Path::new(&out_dir).join("main.rs");
 
-        let mut registry = syntex::Registry::new();
-
-        serde_codegen::register(&mut registry);
-        registry.expand("", &src, &dst).unwrap();
+        serde_codegen::expand(&src, &dst).unwrap();
     }
 }
 
diff --git a/examples/serde-syntex-example/build.rs b/examples/serde-syntex-example/build.rs
index b1aadd78..b034d05f 100644
--- a/examples/serde-syntex-example/build.rs
+++ b/examples/serde-syntex-example/build.rs
@@ -12,10 +12,7 @@ mod inner {
         let src = Path::new("src/main.rs.in");
         let dst = Path::new(&out_dir).join("main.rs");
 
-        let mut registry = syntex::Registry::new();
-
-        serde_codegen::register(&mut registry);
-        registry.expand("", &src, &dst).unwrap();
+        serde_codegen::expand(&src, &dst).unwrap();
     }
 }
 
diff --git a/serde_codegen/src/lib.rs b/serde_codegen/src/lib.rs
index 52ca7912..3a8e94b1 100644
--- a/serde_codegen/src/lib.rs
+++ b/serde_codegen/src/lib.rs
@@ -22,6 +22,11 @@ extern crate syntax;
 #[cfg(not(feature = "with-syntex"))]
 extern crate rustc_plugin;
 
+#[cfg(feature = "with-syntex")]
+use std::io;
+#[cfg(feature = "with-syntex")]
+use std::path::Path;
+
 #[cfg(not(feature = "with-syntex"))]
 use syntax::feature_gate::AttributeType;
 
@@ -31,6 +36,13 @@ include!(concat!(env!("OUT_DIR"), "/lib.rs"));
 #[cfg(not(feature = "with-syntex"))]
 include!("lib.rs.in");
 
+#[cfg(feature = "with-syntex")]
+pub fn expand(src: &Path, dst: &Path) -> io::Result<()> {
+    let mut registry = syntex::Registry::new();
+    register(&mut registry);
+    registry.expand("", src, dst)
+}
+
 #[cfg(feature = "with-syntex")]
 pub fn register(reg: &mut syntex::Registry) {
     use syntax::{ast, fold};